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Discussion Starter · #1 ·
Please help.

I've got long standing performance issues with my 03 plate V6 4motion and I'm at a bit of a loss (to say the least)

I've had the car 18 months from new and its coming up for 28,000 miles.

The car seemed fine when I bought it (as far as I could tell), but I started to notice a drop off in the perfomance, I guess from around 10,000 miles onwards, up to were I am now.

The car got very lumpy, a little noisy and I had to 'make' it move rather than the effortless drive it once was.

After numerous visits to local VW (!), and getting the usual 'no fault found in the ecu blah blah blah' disclaimer, I just happened to throw in a tank of super unleaded. The car was transformed into a performance car again, literally straight off the petrol station forecourt!

The power was staggering, throttle response perfect, and the engine/ exaust tone returned to the nice 'tinny rasp' which it used to have.

Great problem solved - I thought..

Within a couple of weeks, the car's performance started becoming irratic - great for a couple of days, lumpy and unresponsive for a couple, until eventually over the course of a couple of weeks the car's perfomance dropped back off to where it was previously.

Just to clarify ...the difference in performance between a 'good' week and a 'bad' one is amazing - When running poorly, I couldn't get anywhere closer to peak output which is at 6200 I believe, without first getting a 'breathless' feeling - However, when its running well, it pulls easy, smooth and strong, right through 6200....I stopped at 6600! - This isn't something I do everyday for obviousl reasons, but the car pulls like anything when running well.

So...I tried BP Ultimate - same happened again - brilliant, powerful, smooth for a couple of weeks, then irractic, and eventual drop off.

I continued the experiment using optimax, and additives such as 'de-toxic' which again worked great for a while.

I eventually went back on to BP Ultimate and the performance has generally been below par apart from the occasional 'good' week.

Anyway, after many frustrating months (and ??? of 'Ultimate' I decided to have a 'Superchip' fitted - I know about AMD and considered that, butthe garage able to do the superchip was local to me and I was aware a no. of people had been unsatisfied going down the AMD route.

So, last monday I had the 'Superchip' done and turned up to collect the car, in anticipation..

The test drive was disapointing to say the least. The car seemed rough and whilst not any worse, didn't seem any better at all. The Garage reckon that they'd checked power output before and after and that original output was fine and the superchip had made a 16bhp improvement.(no read outs available!?)

I relucantly paid the ?295 and left. I emailed Superchips the following day asking for a refund and a second opinion.

They eventually got back to me yesterday, inviting me to return to the garage and request a 're-fit'.

However, a strange thing happened last week.. The car had a full tank of BT Ultimate in it when the superchip was fitted last monday and I needed to fill up around thursday. I thought, well no point using BT Ultimate any more, and proceeded to put a tank of Texico super in there.

Over the course of thursday, friday, and this weekend, the performance gradually improved, and has continued to improve, even today. It's almost like, every time I turn the engine off and come back an hour later, the car has adjusted up even more.

Tonight for instance, I got home at 5pm, popped out at 7pm and the car was even quicker and smother than two hours previous.

I wonder how its gonna be tomorrow - its a trill to drive at the moment.

To the point where, a few days ago, I was driving it really hard to 'make it go' - now it will go as quick, using about half of the rev range? If I put my foor down, it realy does fly.

So...I don't know whether this a short term improvement, or whether the performance will hold, due to the ecu setup change.

Its almost been like the ecu can't decide how it wants the car to perform.

Unfortunately I don't have any technical knowledge, which doesn't help when trying to explain the problems with the car to a garage. They only see a snap shot on the day and haven't got the time to spend anyway, whereas I drive it everyday and know within about 30secs whether the cars' having a 'good' or 'bad' day.

I've ordered a 'carbonio' cold air induction kit as I thought that this might help the situation as the car does seem worse when warm, but that led me to read articles about 'MAF sensors'

Could this be the cause of my intermittent problems and if so, can I check / diagnose / change maf senors myself? Is this something that VW would have picked up if a problem.

Please - someone help. I really want to enjoy this car. I bought VW, and the V6 in particular because I thought I'd get good reliable 'high' end performance.

Unless I can resolve this once and for all, I think I'll have to sell it and I won't be risking VW again.
 

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Hi Sven, welcome to the world of VW tuning. My 4motion was a big leap up in both handling and performance from the alfa 156 i was previously driving, but already i'm getting dismayed at the querks with the car and the lack of tuning options.

I too had the superchips tuning option, my bhp is now upto 215-220 on a dyno (@ topgear in doncaster), but the readings for torque have dropped! i'm gonna have another dyno run done somewhere else just to clarify the figures.

I wouldn't bother with the cold air intake, by all accounts the VW set up on the V6 is a reasonable piece of kit and the cold air intake won't really make that much difference. Plus, the existing airbox certainly won't be the cause of your problems, so it'll be an expensive way of not curing the running problems.

My belief is that after an AMD re-map or a superchips conversion, you've got a couple of BHP left to get from a decent exhaust and maybe another couple from some decent platinum tipped spark plugs. In either case you'll max the V6 out at about the 230bhp figure. Sadly, after that there'se no where to go except turbo/supercharger conversions, usually good for a total figure of around around 300bhp but cost anywhere between ?3-?6k or the other option is nitrous, gives and extra 50bhp squirt on tap for an installation fee of around ?1200.

In my opionion you should get a chip, an exhaust, some decent plugs and leave it at that. Oh, and get a set of Eibach springs to firm up that handleing, the body roll and the bounce are a pain in the ass. I never bothered with the 18" wheels (not that i wouldn't like some) or the R32 anti roll bars, just adding the Eibach springs has got rid of the roll and the wallow sufficiently to rag the *** off it round most country lanes.

As far as the petrol goes. I've run on both Optimax and supermarket rubbish, but i've never found any performance or running improvements between the two. I do however carry on using Optimax as it is suggested that it will improve the overall life expectancy of the motor.

I wouldn't put the problems your suffering down to either air intakes or petrol, there's quite obviously a fault with the engine management. If the superchip hasn't cured it, i suggest you take up their offer of a 're-fit' and get some garage time and diagnostic time out of them. If that doesn't cure the problem your gonna have to pay for some time at either AMD or a REVO specialist. If they can't help i doubt anyone can. Perhaps take a look at the VAG-com forum on this site and see if you can hook up witha site member who is willing to plug in the diagnostics and spend soem time helping you with the running problems.

Let me know how you get on, as a fellow V6 owner i'm always interested in tuning and diagnostic tips.

Ps - for the record, my next motor will be the Audi S4 2.7 twin turbo, quattro (superchipped) upto 350bhp. It's great value (and performance) for money and the tuning options seem a lot mor fun. In the meantime though i'll be gettinh as much bang for my buck as i can oput of the 4mo.

Let me know how you get on.
 

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pss - cleaning the maf is a better bet than replaceing it.

The Mk4('99.5+) MAF sensor is inferior and is a poorly designed part made by Bosch (just like the window regulators).

Here is what causes them to fail:

The Mk3('94-99) MAF sensors will heat up to 1000 degrees Celsius for one full second to burn off dirt and contaminates when you shut the engine off. The Mk4 MAF sensor does not have this feature. Dirt, oil, and other contaminates build up during normal everyday driving causing the MAF sensor to eventually fail. Some enthusiasts install aftermarket intakes (K&N, ITG, and CAI kits) which use special oils to help attract dust. Because the engine is essentially a vacuum, it sucks some of the oil right onto the MAF sensor, resulting in accelerating the contamination.

Your best bet is to clean your current MAF sensor, rather than purchasing another inferior part that will fail in the near future.

Use isopropyl alcohol - found in common carb cleaner spray. Check out other posts on this forum for more detailed instructions on maf cleaning.
 

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Discussion Starter · #4 ·
Thanks for that guys.

Unfortunately, I've ordered the induction kit already and its on route as I speak -I'll give it a go anyway - reading a couple of articles where it has been fitted on the R32, it seems to imply a noticeable difference.

It's not so much that I want to squeeze every last bhp out of it - all I'm looking for at this point is some consistency in performance - when it running well I'd be more than happy with it. It's just that from week to week you never know what you're gonna get.

I have taken it into VW when its going badly - they just say 'its within acceptable parameter' - the ecu doesn't show any faults, so - if I then take it back on a good week, they've got nothing to measure the perfomance against.

I'll check the forums regard the MAF sensor - I know what it stands for but could someone tell me what is does, how it effects perfomance, where it is - how easy to get to and clean...

thanks a lot
 

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Mass Air Flow sensor. It is a small unit that sits in the large air intake pipe between the air filter and the engine. It detects air flow through the pipe and produces a voltage which varies depending on the air speed. This voltage is monitored by the ECU and is part of the fuel metering system.

When the MAF dies the ECU tends to run the engine lean as it has no way of determining how much air is being sucked into the pots. This leads to a noticeable lack of power output from the engine.

Replacement is very simple and can be performed by the driver in less than 15 minutes. VW have dropped the price of their MAF considerably as they are known to fail regularly.

Follow the large diameter pipe from the air filter box. The MAF sits in a cylinder usually about half way along. It is black, approximately two inches high and will have a small bundle of wires coming out of the cap.

To remove - take off the wired cap. There are a couple of Torx screws holding the unit in. Remove those. Remove the MAF then clean the unit or install new one.
 

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I was a little dissappointed with the performance of my 2001 6 4motion in standard form, I had a remap at AmD and the car improved noticably, up to 224bhp from 210 and torque from 195lb.ft up to 222lb.ft. I would recommend this conversion for anyone, the car seems to pull a lot better throughout the whole rev range particularly from about 3000rpm. I have tried all fuels from supermarket stuff to optimax and really haven't noticed much difference at all.
 

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Funny you should say that car's running better on super. Been on Optimax in my V5 for two years, last month switched to super and exactly the same thing, engine seemed perkier, more reponsive and smoother.

I reckon it's to do with BP Ultimate, see my thread

http://www.uk-mkivs.net/forum/topic.asp?TOPIC_ID=40554&SearchTerms=,bp,ultimate

It's an audi related post but given the similarities in the engines can easily see that this could apply to VW too.
 

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Quote: posted by daniel99weed on 12/10/2004 17:20:13

I was a little dissappointed with the performance of my 2001 6 4motion in standard form, I had a remap at AmD and the car improved noticably, up to 224bhp from 210 and torque from 195lb.ft up to 222lb.ft.

A little birdie told me that all a remap for the NA V6 does is advance the timing and relieve you of ?300. Is this true? Discuss.

Welcome to the forum mate, sorry to hear about your problems and interesting you found premium fuels had a profound effect; its a recurring topic around here. Many swear by it, but after prolonged testing I have found no benefit whatsoever. For me this is backed up by the lack of any hard evidence in the public domain, even from Shells people (Ive asked), as to its effects. I have read posts on other forums where the argument is raging on between F360 and 911 owners, and even there they can't make up their minds! There was a test in the Times but it was far from conclusive...so who knows.

Anyway let us know how the induction kit works out.
 

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Discussion Starter · #9 ·
Thanks for the feedback

I think I'll take a look at the maf sensor tomorrow and see whats going on there.

The performance can be so different, its got to be something like that.

You would think that a VW garage would check that as a matter of course and / or the diagnostics program would pick it up - Someone's now going to tell me ..'thats not necessarily the case'

cheers
 

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Quote: posted by Mikedav on 12/10/2004 21:53:28

A little birdie told me that all a remap for the NA V6 does is advance the timing and relieve you of ?300. Is this true? Discuss.

Wilko?

He mentioned it in a thread a few weeks ago, you should be able to advance your timing using Lemmiwinks and a vagcom lead, pop in some Optimax and Octane booster then away you go!!

You will need to check the timing with vagcom to make sure you dont go too far.
 

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Discussion Starter · #11 ·
Yeah, done the optimax and octane booster a few time over the last few months - as I mentioned in the original post, it seems to work really well for a while, but then the power dropped off again.

Trouble is, it becomes a little expensive when you're talking optimax / ultimate prices, plus a tim of booster / de-tox on top at ?5 - ?10 extra every tank full, just to replicate the original performance of the car. - It just ain't right that I have to do this.

I had the superchip fitted last monday and today, the car is still flying along - really smooth and quick - I'm running on texico super at the moment, so I'll carry on with that for the next week and if the performnace holds, hopefully the superchip will have sorted the problem.

I'll also fit the carbonio CAI when that arrives and see how we go.

It does strike me that, judging on the performance of the car at the mo, I have been really missing out - I would say that on the basis of the performance now (and I mean before the superchip) I reckon I've been running for the last 15,000miles at about 75% stock power, not to mention the new found responsiveness, and smoothness.

Is this a ecu or maf sensor fault indicator, or both, or something else? At the moment it seems like ecu, but if the power drops again, I obvious need to look elsewhere for the problem.

I've proved that the power is in the car - it's just maintaining it.

Rest assured, I've been holding up the 4motion 'rep' this week against inferior competitors while the going is good![:)]

When its bad, it can be embarrasing and I don't think I'd take on my dad in his Fusion[:I]
 

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It was me wilko mentioned the timing advance too, I tried it and it didnt work lemmiwinks cant read the v6 ecu. I have the same problem with my v6, read my previous post about slow motion getting it ass whooped by a mini!.

The only failsafe way of testing the MAF is with vagcom, I have tested mine and it reckons it was ok but as the problem is variable I reckon that the fault could be intermittent, the only way I can find out is to run vagcom over an extended period, but i dont really fancy lugging my laptop/inverter for thenext month. Next month I may well just change the MAF anyway as the variable performance is doing my brain in.
 

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Sven,

I have read similar things on different forums to the problems you describe. Having owned many versions of the 1.8T in various tuned forms I always felt that the V6 would naturally be a bit disappointing in that the number of potential mods for the V6 would be limited and it's also normally aspirated, therefore no "on boost" cheek deforming acceleration.

However I wanted a V6 for its ability to deliver smooth steady torque all the way through and be a great 'A' road/motorway cruiser, handling in all weather and fun in the twisty stuff. However, like you, I am finding the up and down nature of the performance is really testing and I'm not at all confident when it comes to overtaking... will the power be there or not?

My car is a 53 plate and only just a year old with 10K on the clock. I have been running Sainsburys Super as my experience is that both Optimax and Ultimate actually makes little difference. Sainsburys Super is only 2p more than ordinary so what the hell.

Ambient temperatures don't seem to make a great deal of difference, fuel doesn't make a difference, new oil and plugs doesn't make a difference so it can only be air/fuel mix or ignition/timing.

So, I am about to go down to my local VW dealer and see if they have any explanation (I'm not expecting them to have one, as it probably won't come up on vagcom). After that I'm off to spend some money with AMD, they have always put the smile on my face with everything else I've put their way.

If that doesn't solve it I may end up selling the car, I hope that it doesn't come to it as the potential is all there, I just hope it can be tapped!

I'll let you know how I get on!
 

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Just to give you guys some info on the petrol situation:

Super is refined as an unleaded fuel with an octane of around 97.

Its a stand alone fuel made independant of normal unleaded and by far the best fuel to use assuming timing is adjustable to get the most from it.

Optimax is different entirely. Its made from standard 95 unleaded, with Octane boosters to make it peak at 101 octane as it leaves the depot. Although a higher octane initially than Super, its also unable to maintain its octane. By the time its reaches petrol stations and is purchased, its octane will be closer to 98.

It also contains strong cleaning agents which some older cars just dont like. Its really designed for the newest of cars as a fuel to be used all the time.

If you use it, dont expect any gain over Super, its often more expensive, and unless got from a station with a high turn over and regular deliveries, you are wasting your money on it and might as well buy 95.
 

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I also found this info, hope it helps y'all make your minds up at petrol pump time....

Try texaco super mate if you can find it. According to a couple of my friends there petrol is fair superior to any other "super" petrol.

Texaco is a subsidary of ESSO and both use the same petrol.

There are basically 3 companies which supply fuel to the UK. ESSO, BP, AND SHELL.

Each sells to all the other names you find.

JET, FINA, Q8 and a few other smaller outlets all use SHELL.

TEXACO and TOTAL use ESSO,

Supermarkets use Eastern Block fuels, which are primarily designed for the 91 Ron continent market.

These are upgraded in the UK to UK specs by using Butane gas.

Hence to avoid.

BP Ultimate is just its old Super grade cleaned up a bit.

IE. It goes through another filter at the refinery.

Not a bad fuel though, second only to ESSO in quality.

Its Diesel is the best in the world for all you Diesel owners.

OPTICRAP. Need i say more. All grades supplied by Shell.

Might as well fill from your local FINA station and pop a bottle of Halfarts octane super duper booster plus in.

ESSO 95 and 97 = If you want every pennies worth in quality petrol, look no further.

Get it at your local TOTAL, TEXACO or ESSO now !

:eek:)
 

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Discussion Starter · #16 ·
Thanks for all the info guys. It really does help to know that I'm not the only one experiencing intermittent problems.

Talk Torque,it sounds like you got almost the same issue - runs really well for a while, then goes flat and noisy.

It does seem to run much better on the texaco super than other brands.

The problem is diagnosis - vw will check it with vagcom at the time, but after numerous visits, I've come to the conclusion that the're just not interested -no fault shown - no problem - in their opinion.

I too suspect that its a setup (timing/air,fuel mix) issue - can't believe its the ecu - time will tell. If the performance drops off with the superchip fitted, then it must be something to do with the setup.

At the moment (4 days in a row now) the car's fine - running with texaco and a superchip.

Putoline, thanks for all the fuel info - very intresting stuff, and it does seem to support my experience with texaco super.

The carbonio induction kit has just turned up, so I'm gonna attempt to fit that, whilst cleaning the MAF sensor at the same time.

Right! - anyone know how to get the bumper off?[:I]
 

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Great info on fuel, thank you for sharing that. I have a Texaco near me but I don' think they stock Super, will go and ask.

I went to VW today and the result is posted on another thread "V6 4mo engine problem" so I won't bore you all with it again.

Getting bumpers off, try MikeDav's site http://www.borabase.hostrocket.com/

It's off to AMD then... I'm glad I budgetted for this when I bought the car... mutter... mutter... mutter
 

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Discussion Starter · #18 ·
Well guys,

Fitted the carbonion CAI last night to my recently superchiped 4motion - see previous posts.

Fitting;

It didn't seem necessary to remove the bumper on reading the instructions and wasn't, but it was a bit of a fiddle getting the piping into just the right position. Contrary to the instructions (after several failed attempts) I found it best to fit the filter last. If you fit the fliter first it's pretty impossible to maneouvre the adapter ( which sits between the carbon pipe and filter) through the small gap in the engine compartment. Get all piping into place, clamped up lightly, then jack up front nearside, partially remove plastic cover to wheel arch to expose lower engine compartment. Finally get yourself underneath and push filter onto piping adapter (couldn't get enough purchase without jacking up car and getting underneath).

I should have waited till the weekend really and done it in the daylight - but couldn't[8D]

The results;

Early days yet, but it seems like a little of the low end torque (say between 1,000 - 2,500 rpm) may have been sacrificed, but blimey, its worth it for what happens from 2,500 all the way up to 6,800!!

It may be deceiving but it really comes to life from 2,500 upwards and really wants to go! - I've always found the car to be better driven with short acceleration between the gears, using the low down torque, as not much would happen from 4,000 upwards. things seem to have changed - it seems more than happy to pull right through the rev range now, and to that end, the delivery is very smooth with no noticeably peaks or flat spots.

and it sounds great! - drive it easy and it sounds no different than before - push your foot down and it sounds like how a 2.8v6 should!!

As I said, it's early days, so I'll let you know how I go over the new few days - at the moment, things are looking really good.
 

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Hi Sven,

The CAI sounds cool and it sounds like you had fun putting it all together.

Out of interest, what do you play in your band (ie: what instrument)?
 
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